Ultimate Strain and Anisotropic Behavior in Corrugated Composites

In some applications such as morphing technology, high strain and anisotropic behavior are considered a good advantage. The corrugated composite sheets due to their special geometries have a potential of high deflection under axial loading. In this research, to investigate the strain and anisotropic behavior of corrugated composite sheets some glass/epoxy samples with Quasi-sinusoidal, trapezoidal, rectangular and triangular geometries were manufactured and put to tension and flexural tests in the longitudinal and transverse directions of corrugation. Then, in order to determine anisotropic behavior of corrugated sheets two concepts were introduced: tensile anisotropic and flexural anisotropic criteria based on which anisotropic magnitude was investigated theoretically and experimentally. This research used Yokozeki’s theoretical model for quasisinusoidal geometry and his model for trapezoidal, rectangular and triangular geometries. Experimental results showed that corrugated sheets have a strain more than 90%. In the corrugated samples, the strain magnitude was dependent on amplitude and pitch of elements; in other words, it was dependent on the number of elements per length unit. Generally, the Quasi-sinusoidal corrugated sheets have a high strain (more than 50%). Experimental results of trapezoidal sheets showed that amplitude of the elements is one of the most important parameters in the ultimate strain. Generally, increasing the amplitude leads to the growth of the ultimate strain